<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style type="text/css">
        .div1:before {
            content: '';
            background-image: url('./bg4.jpg');
            background-size: 150px 150px;
            /* display: block; */
            height: 10px;
        }
        
        .div1:after {
            content: '';
            background-size: 130px 120px;
            background-image: url('./bg4.jpg');
            /* display: block; */
        }
        
        .div1:before,
        .div1:after {
            content: '';
            margin: 0 10px;
            background-size: 170px 170px;
            background-image: url('./bg4.jpg');
            border: 1px solid red;
            width: 40px;
            height: 40px;
            display: inline-block;
        }
        /* div {
            width: 100px;
            height: 100px;
            border: 1px solid red;
        } */
        
        .div-father {
            width: 300px;
            height: 300px;
            background-color: red;
            margin-top: 20px;
            /* border: 1px solid red; */
            /* padding: 1px; */
            overflow: hidden;
        }
        
        .div-son {
            width: 150px;
            height: 150px;
            background-color: pink;
            margin-top: 50px;
        }
    </style>
</head>

<body>
    <div class="div1">我是div</div>
    <div style="padding-bottom: 100px">
        <p style="margin-bottom: 30px"> fsdf</p>
    </div>
    <div style="margin-top: 50px">mamd</div>
    <div class="div-father">
        <div class="div-son"></div>
    </div>
</body>

</html>